Adam Lanza also had a mental illness, and he killed 26 people, including 20 children, at an elementary school in Newtown, Conn.

Jared Lee Loughner had a mental illness, too, and he killed six people at a supermarket and gravely wounded an Arizona congresswoman.

When mentally ill killers receive such notoriety — with their actions almost always attributed to the mental illness itself — what happens to the nearly one in four Americans with mental illnesses who never engage in violent behavior?

News accounts too frequently add to a pervasive fear and disdain, mental health experts say, citing a stigma with deep roots in American society. And it is a stigma that is not only based on misconception, experts and advocates say, but one with serious and damaging repercussions.

“The problem is that this becomes the only public face of severe mental illness that the general public has,” said Steven Marans, a professor of psychiatry at Yale University who works at the nationally renowned Yale Child Study Center. “The bottom line is a very, very small percentage of severely psychiatric people are involved in violent crime. Period.”

“The mental illnesses that are more likely to produce violence than others are typically untreated psychotic disorders,” said Xavier Amador, a clinical psychologist in New York and the former science director at Columbia University’s Schizophrenia Research Unit. Psychosis, which is a disconnection from reality, can appear in many mental illnesses but is generally quite rare.

The medical professionals who examined James Holmes, both before and after the attack, struggled to establish a definitive diagnosis. That Holmes should be on an anti-psychotic medication, however, was an area of agreement. Loughner, the Tucson shooter, was only diagnosed with schizophrenia and medicated with anti-psychotics after the attack, though he had been exhibiting symptoms for months beforehand.

People with schizophrenia, Amador said, are “no more violent than the general population provided they are in treatment — effective treatment.”

Experts expressed exasperation with the ease in which news accounts often link mental illness to horrific incidents.

“People with schizophrenia are more dangerous than the average person, but so are men. So are young men,” said Patrick Corrigan, a psychology professor at the Illinois Institute of Technology and an expert on mental illness and stigma, stressing that the correlation is not nearly strong enough to justify the stigma that exists. Being young and male is a better predictor of violence than having schizophrenia, he said. And schizophrenia is one of the most severe mental illnesses.

“Mental illness is a very, very messy term,” he said. “People who study this might understand they are different, but the general public doesn’t. For the general public, you’re schizophrenic, you’re bipolar — you’re all nuts.”

Mental health experts and advocates stressed just how effective treatments are. But one of the biggest barriers to treatment is the very stigma around mental health.

Only 60 percent of U.S. adults with a serious mental illness received treatment in the past year, according to the National Alliance on Mental Illness, or NAMI, an advocacy group. Fears of being discriminated against or viewed differently discourages people from seeking treatment. Those with a mental illness, predictably, feel the weight of stigma far more acutely. They were significantly less likely than those without a mental illness to believe that people “are caring and sympathetic to persons with mental illness,” according to a 2007 study by the federal Centers for Disease Control and Prevention. They were also less likely to have confidence about the effectiveness of treatment.

Beyond fear of seeking treatment, stigma also leads to discrimination and shame, Corrigan said. The best tool to combat stigma, experts agree, is testimony from those with mental illness.

“People’s understanding of mental illness can change by interacting with people with that lived experience,” said Scott Glaser, executive director of NAMI’s Colorado branch. “It’s common and it just needs to be talked about and de-stigmatized.”

“The progress happens one person at a time. It doesn’t happen systematically.”

“We all know people with mental illness,” said Amy Watson, a professor at Chicago’s Jane Addams College of Social Work who has researched and written extensively on mental illness and stigma. Those people may be in recovery, going to work and raising families, and they keep their illness to themselves to avoid alienation. “It’s suddenly something they feel like they need to hide.”

But recovery stories are common and generally do not drive news coverage, while violence does.

“Recovery is boring,” Corrigan said. “The guy on the street who is psychotic, screaming into the wind, is really the exception. James Holmes is a grotesque exception.”

The Fitzsimons Golf Course may, after 20 years of rumors, be closing at the end of this year to make way for bioscience master plans. As staff and regulars await a final date, they reminisce on the course’s nearly 100 years of history.